Pharside I took some time to carefully examine the scant information provided by the "kit" vendor & "if" the photos and description are accurate I'm led to believe that your Gt-5 (38 mm) stroke engine bottom end and clutch/drive train components can be used with the cases and cylinder provided. The vendor states that case bearings are installed & all gaskets are included.
I'm also quite familiar with "reed type" engines & also the various vendor hp claims; from stock to highly modified & I think most oversell their wares. Especially import distributors who often pay others to reverse engineer the design work of dedicated engine builders/tuners who are often a part of actual race efforts, as well as provide complete engines & parts to hardcore racers. Engine builders who can and do wring out the 10 hp or more from 66 cc, but very few of us are going to duplicate that kind of output. Real race engines put to work on the street are typically a pain to ride & require constant tuning and tweaking to keep them creating top hp. A fresh engine that "actually" dynos 7 hp might drop off to 5 or 6 hp in just a few hours of normal street riding...just reality.
I'm not trying to talk you down from buying the kit, heck I'd buy the cases by themselves if I didn't have to buy the other unknown components that are included. Just to play with, but I'd buy an actual Arrow reed, carb & jug and use the GT-5 components to complete it. Same with the head. I won't buy a head from a vendor that won't because they can't at least tell me what the combustion chamber volume is.
Pharside chasing high hp really begins with well balanced rotating assembly's & good parts clearances or the high output engine may be fast but won't last.
Best of luck, Rick C.
